Insufficient length checks

[kloetzl]

The following code is confusing me.

Mash/src/mash/hash.cpp

Lines 14 to 24 in aabd592

	#ifdef ARCH_32
	char data[use64 ? 8 : 4];
	MurmurHash3_x86_32(seq, length > 16 ? 16 : length, seed, data);
	if ( use64 )
	{
	MurmurHash3_x86_32(seq + 16, length - 16, seed, data + 4);
	}
	#else
	char data[16];
	MurmurHash3_x64_128(seq, length, seed, data);
	#endif

On x86 there is a check that the length is sufficient, but only for 32bit hashes. For 64bit hashes, length - 16 may still be negative and lead to weird behaviour in MurmurHash3_x86_32. On x64 nothing gets checked. Am I missing something?

[kloetzl]

I realised that this might not be that much of an issue, because there are checks in place prior to calling this function that ensure enough data is available.